| 摘要: |
| [目的]研究不同水平钴对草鱼幼鱼生长性能、机体营养成分、组织钴含量和血液指标的影响,以确定草鱼幼鱼对饲料中钴的适宜需要量.[方法]选取初始体质量为(3.21±0.35) g的草鱼(Ctenopharyngodon idella)幼鱼,随机分成6组,其饲料中钴含量分别为0.05(对照组),0.13,0.22,0.44,0.95和1.63 mg/kg,每组设置3个重复,每重复60尾,饲养试验周期为70 d.[结果]饲料中添加钴显著提高了草鱼幼鱼的特定生长率、增重率和蛋白质效率(P<0.05),但对存活率无显著影响(P>0.05),当饲料中钴含量为0.22 mg/kg时,草鱼的特定生长率、蛋白质效率和增重率最大,饲料系数最低,并与其他各试验组差异显著;饲料添加钴对草鱼全鱼水分、粗脂肪、粗蛋白和灰分含量无显著影响(P>0.05);当饲料中钴含量为0.22 mg/kg时,草鱼幼鱼肝脏、肾脏和肌肉中钴含量最大,且显著高于钴含量为0.05,0.13和1.63 mg/kg试验组(P<0.05), 而当饲料中钴含量在0.22～0.95 mg/kg时,各试验组之间草鱼幼鱼肝脏、肾脏和肌肉中钴含量无显著差异(P>0.05);饲料添加钴可以增加草鱼幼鱼血红蛋白含量(HGB)、血小板计数(PLT)、红细胞压积(HCT)和红细胞计数(RBC),当饲料中钴含量为0.22 mg/kg时,血液中血红蛋白质量浓度、血小板计数、红细胞压积和红细胞计数均达到最大值,与钴含量为0.05 mg/kg试验组差异显著(P<0.05).[结论]基于特定生长率和肾脏钴含量折线法分析,草鱼幼鱼获得最佳生长和组织钴累积水平时,对饲料中钴的需求量约为0.20 mg/kg. |
| 关键词: 草鱼 钴 饲料试验 生长性能 机体营养成分 血液指标 |
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| 基金项目:国家科技支撑计划重点项目，上海市教委重点学科建设项目 |
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| Dietary cobalt requirement of juvenile Ctenopharyngodon idellus |
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| Abstract: |
| 【Objective】 A feeding trial was conducted to estimate the optimum requirement of dietary available cobalt for juvenile Ctenopharyngodon idellus.【Method】 Cobalt chloride was added to the basal diet at 0,0.1,0.2,0.4,0.8 and 1.6 mg/kg diet providing the actual dietary value 0.05(control),0.13,0.22,0.44,0.95 and 1.63 mg/kg diet respectively.Casein and gelatin were used as protein sources,dextrin as carbohydrate source and fish oil and corn oil as lipid source respectively.Each experimental diet was randomly assigned to triplicate groups of fish,and each group was stocked with 60 fish ［initial body weight,(3.21±0.35) g］.Fish were fed three times daily (9:00,13:00 and 18:00) to satiation for 70 days.During the experimental period,the water temperature fluctuated from 25 to 28 ℃,and dissolved oxygen was approximately 5.0 mg/L.【Result】 The results showed that the weight gain rate,specific growth rate and protein efficiency ratio of the juveniles increased significantly with the increase of dietary cobalt levels (P<0.05).There were no significant differences in survival rate (P>0.05).Maximum weight gain,specific growth rate,protein efficiency ratio and minimum feed efficiency occurred for group at 0.22 mg/kg dietary cobalt,which were significantly different from the other five groups (P<0.05).Supplementation of dietary cobalt had no significant effect on the moisture,crude protein,crude liquid and crude ash content of the juvenile (P>0.05).When the juveniles were fed 0.22 mg Co per kg diet,the cobalt contents in liver,kidney and muscle reached the peak,which were significantly higher than 0.05 mg/kg group,0.13 mg/kg group and 1.63 mg/kg group(P<0.05).There was no significant difference in cobalt content in liver,kidney and muscle when the fish were fed the diets of 0.22-0.95 mg Co per kg diet (P>0.05).Supplementation of dietary cobalt increased hemoglobin (HGB),platelet count (PLT),hematocrit (HCT) and red blood count (RBC).These values reached the peak when the juveniles were fed 0.22 mg Co per kg diet,which were significantly higher than 0.05 mg/kg group (P<0.05).【Conclusion】 Broken line regression analyses of specific growth rate and kidney cobalt against dietary cobalt level indicated that the dietary cobalt requirement for optimal growth and accumulation level of tissue cobalt of juvenile Ctenopharyngodon idellus was about 0.20 mg Co/kg diet. |
| Key words: Ctenopharyngodon idellus cobalt feeding trial growth performance nutrient composition of whole body blood parameter |
